34 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Family CAESALPINIACEAE. 

 Genus CASSIA Linnaeus. 



CASSIA CULEBRENSIS, new species. 



Plate 16, fig. 1. 



Description. — Leaves obviously pinnately compound. Leaflets 

 ovate, slightly inequilateral and falcate, with an obliquely acumi- 

 nate, practically equilateral tip, and an acuminate markedly inequi- 

 lateral base. Length about 6.25 cm. Maximum width, about mid- 

 way between the apex and the base, 2.75 cm. ; one side of the lamina 

 15 mm. wide, the other 12.5 mm. wide. Texture mediumly coriace- 

 ous. Petiolule reduced to a thickened proximal part of the midrib 

 extending but 1 mm. below the point of junction of one margin and 

 about 2.5 mm. below the point of junction of the opposite margin. 

 Margins entire, evenly rounded and full. Midrib relatively thin, not 

 prominent, curved. Secondaries thin, numerous, about 10 suboppo- 

 site to alternate pairs; they diverge from the midrib at wide angles, 

 about 70° in the middle part of the leaflet, are nearly straight regu- 

 larly spaced and subparallel in their outward course for two-thirdi 

 of the distance to the margin where the principal ones fork to join 

 in rounded arches the similar branches of adjacent secondaries; the 

 secondaries in the apical and basal portions of the leaflet are regu- 

 larly camptodrome; those toward the tip of the leaflet more closely 

 spaced. Marginal tertiaries camptodrome, internal tertiaries mostly 

 obsolete. 



This type in its general form and the character of its base and 

 petiolule indicates that it is a leaflet of a pinnate leguminous leaf. 

 Its general appearance suggests comparisons with the genera 

 Sweetia, Myrocarpus, Toluifera, Cassia, and Sophora — the first three 

 confined to tropical South America and the last two cosmopolitan in 

 the existing flora. While the evidence is not conclusive, I prefer to 

 consider it more closely allied to Cassia than to the other genera 

 mentioned, particularly as the venation characters are such as I have 

 considered referable to Cassia in my studies of the fossil floras of the 

 southern United States. No species related to the Panama form is 

 known from the Oligocene of the United States. 



The modern species of Cassia are very numerous, upwards of 400 

 having been described. They comprise herbs, shrubs, and trees of 

 varied habitats in the warmer parts of both hemispheres, particularly 

 tropical America. The fossil species are also numerous and the 

 generic history goes back to near the base of the Upper Cretaceous. 

 The genus has been continuously represented in the warmer parts of 



